Update documentation about dependency to run docfx (#1000)
Update documentation about dependency to run docfx (#1000)


LordZoltan/docfx,superyyrrzz/docfx,pascalberger/docfx,DuncanmaMSFT/docfx,dotnet/docfx,superyyrrzz/docfx,928PJY/docfx,928PJY/docfx,DuncanmaMSFT/docfx,LordZoltan/docfx,hellosnow/docfx,dotnet/docfx,hellosnow/docfx,LordZoltan/docfx,LordZoltan/docfx,928PJY/docfx,dotnet/docfx,superyyrrzz/docfx,pascalberger/docfx,hellosnow/docfx,pascalberger/docfx